Q10: What is OpenID Connect (OIDC) and how does it extend OAuth 2.0?
OpenID Connect (OIDC) is an identity layer built on top of the OAuth 2.0 framework. While OAuth 2.0 handles authorization (granting access keys to resources), OIDC extends it to perform user authentication.
OIDC Additions to OAuth 2.0:
- ID Token: A standardized JWT containing user identity profile attributes (claims like
sub,email,name). - UserInfo Endpoint: A protected API endpoint returning detailed user profile attributes.
- Standardized Scopes: Predefined scopes like
openid,profile,email.
Key Takeaways
- OIDC = OAuth 2.0 (Authorization) + ID Token (Authentication).
- Always include the
openidscope in authorization requests to trigger OIDC behavior.